Gas turbines are increasingly being subjected to higher temperatures and/or increased temperature gradients in order to increase efficiency. Such temperature conditions can result in thermal fatigue. Some gas turbine components have geometric features, such as edges, that augment the effect of such temperature conditions.
Thermal fatigue can initiate/form cracks or other fatigue features, expand cracks or other fatigue features, and/or propagate/extend cracks or other fatigue features. Such cracks or other fatigue features can be undesirable for operational and/or cosmetic reasons. Often, such cracks or other fatigue features limit the capability of components and/or materials from being used under high temperatures and/or large temperature gradients.
Known processes include treating regions of components that are subjected to high temperatures or large temperature gradients. Some processes involve using high amounts of energy to modify the surface of such components, thereby resulting in an increased resistance to thermal fatigues. Such processes suffer from the drawback that they can be costly and can be limited in applicability based upon where such processes can be performed.
Other known processes include using a single material that is resistant to thermal fatigue. Such materials can be expensive and can include other properties that are not desirable. Previously, processes did not use multiple materials due to the additional steps and expense as well as potential compatibility issues associated with using multiple materials.
A turbine component and a process of fabricating a component not suffering from one or more of the above drawbacks would be desirable in the art.